Norton Service Release Database N2/06

SERVICE RELEASE N2/06

NATURE OF RELEASE: Crankshaft Main Bearings. MODELS AFFECTED: 1972 models (commencing engine number 200, 004) DISTRIBUTION: Worldwide (Trade only) EXPLANATION: Field experience with 1972 models (incorporating two single lipped roller main bearings) indicates a small, but significant premature roller main bearing failure rate. Reported failures have been confined solely to one type of bearing.   ACTION: When replacing defective roller main bearings, ensure the replacement is a Skefco double lipped outer, single lipped inner spool type NJ306, with a specified nominal internal diametral clearance of 0.0008/0.0012ins. (0.02/0.03mm) Prior to fitting (180 Normal). Ensure the crankshaft journals are carefully cleaned up, removing all signs of butts or scoring before fitting the inner spool. Models subsequent to Engine Number 207197 incorporate a nominal increase in bearing housing diameter to overcome any significant tendency to excessive closure of the single lipped outer series of roller bearings. July 1972 Norton Villiers Canada Limited